Absorbance reading apparatus according to the prior art typically reads the absorbance of a biological sample, such as a cell or nucleic acid, by placing the tested sample in a case called cell.
FIG. 24 illustrates the concept of a conventional absorbance reading apparatus. As shown, a sample solution that is to be read is placed in a cell. Irradiation light emitted by a light source is converted into monochromatic light by a spectroscope that is controlled by a wavelength drive unit. The monochromatic light is focused by a lens A into the sample, thus irradiating the sample. Light transmitted by the sample is condensed by a lens B and then converted into an electric signal by a detector.
Such an absorbance reading apparatus is only capable of reading the absorbance of one biological sample at a time. The cell is about 50 mm in height, 10 mm in width, and 10 mm in depth, so that a great amount of sample is required for reading. In another example, the absorbance of a specimen (sample) is measured in a nozzle (See JP Patent Publication (Kokai) No. 2000-258341 A, for example).
In these conventional absorbance reading apparatus, it has been difficult to read the absorbance of a number of samples efficiently in a short period of time because the samples have to be read in cells.
It is therefore an object of the invention to realize an absorbance reading system that can read the absorbance of many kinds of samples in small quantities in a short period of time at once. It is another object to realize data processing whereby data can be processed such that the visual observation of the absorbance that has been read can be facilitated and the results can be output in an easy-to-understand manner. A further object of the invention is to provide an absorbance reading system that enables a desired sample to be recovered for more detailed analysis based on the reading result of absorbance.
In accordance with the invention, a number of wells on a microchamber array are simultaneously irradiated with monochromatic light. Parallel light transmitted by the wells is captured via a telecentric optical system by an imaging camera as an image, and the absorbance of a sample in each well is individually calculated.
The invention provides an absorbance reading apparatus comprising: a sample base for mounting the microchamber array; a light source; a spectroscope on which light from the light source is incident; an irradiation optical system for adjusting the distribution of luminance of irradiation light emerging from the spectroscope; a field lens for enlarging the size of irradiation light transmitted by the irradiation optical system and irradiating the microchamber array mounted on the sample base with the enlarged irradiation light; a one-side telecentric optical system for receiving sample-transmitted light; and an imaging camera for producing image data based on the sample-transmitted light received via the one-side telecentric optical system. Irradiation light transmitted by the irradiation optical system is irradiated onto the microchamber array from an upper plane to a lower plane thereof, or from the lower plane to the upper plane thereof, passing through the wells in a depth direction. The absorbance reading apparatus may be provided with a sample recovery mechanism for recovering the samples in the wells. The absorbance reading apparatus according to the invention is capable of reading the absorbance of all of the wells on the microchamber array within one minute.
In order to read the absorbance of a plurality of samples injected into individual wells provided on a microchamber array, the invention, as the steps of controlling an absorbance reading apparatus, comprises: controlling a light source for emitting irradiation light for reading absorbance; selecting an absorbance read mode from the group consisting of a wavelength scan mode and a chronological scan mode; controlling a spectroscope for selecting the wavelength of the irradiation light; controlling an imaging camera for reading the absorbance of a sample; and storing the absorbance read by the imaging camera in a database. More specifically, the invention comprises the steps of: setting an exposure time of the imaging camera for reading the absorbance of a sample; setting a read start wavelength of the irradiation light for reading absorbance; setting a read wavelength resolution of the irradiation light for reading absorbance; setting a read time for reading absorbance; and setting the number of times of reading absorbance.
The invention preferably comprises the steps of: reading a zero-correction solvent; and reading a tested sample. The invention also comprises the steps of: specifying image data for calculating absorbance out of absorbance calculation image data read by the absorbance reading apparatus; specifying an absorbance calculation region in the specified image data; and calculating absorbance based on the specified absorbance calculation region. The step of specifying the image data for the calculation of absorbance comprises the steps of: displaying, as the image data, an image of the microchamber array in which a zero-correction solvent is placed and an image of the microchamber array in which a tested sample is placed; and specifying an absorbance calculation region on the image data of either the zero-correction solvent or the tested sample. Further, the invention may comprise an optical path length correction step of correcting absorbance reading apparatus-dependent differences in the optical path length on the tested sample, or the step of recovering a desired tested sample. The absorbance reading apparatus may be controlled by a computer program.